Most international models surveyed were in agreement with the IMD outlook for this phase.

Cyclone phase evaluation modelling by the Canadian Meteorological Centre and the Global Forecasting System (GFS) of the US National Centre for Environmental Prediction (NCEP) identically suggested enhanced weather activity in the south-west Bay of Bengal.

North Sri Lanka, the Palk Straits and south-east coast of Tamil Nadu are the areas likely to witness most of the weather, according to these projections.

October 31 and November 1 could be the two dates to watch out during the short term for south-east Tamil Nadu and north-east Sri Lanka, according to GFS predictions by the US Fleet Numerical Meteorology and Oceanography Centre.

Precipitation forecast by the NCEP valid for the week ending November 1, too, said that south-east coastal Tamil Nadu and the rest of its coastal regions may be in for some battering.

Abnormal warming of the south and south-east Bay is what is seen as keeping the basin sufficiently active, the NCEP outlook said.

This active phase is forecast to continue during the following week (November 2 to 10) as well with the ‘push’ coming in from the south to south-east Bay.

LIKELY TYPHOON

According to the European Centre for Medium-Range Weather Forecasts (ECMWF), enhanced activity could be attributed to landfall of the next typhoon-in-making (Mirinae, according to naming protocol) in the South China Sea with a landfall predicted over Thailand on November 3.

After landfall here, the weakened storm is forecast to head west to south-west into Indo-China and a remnant circulation may manage to slip into the Bay of Bengal within the next two days.

This behaviour of this remnant circulation would need to be watched out for signals for reinvigorated storm activity, according to the Roundy-Albany model that tracks storm development.

According to the ECMWF, the causative ‘low’ may take shape east of the Philippines by Wednesday and make a landfall over the most storm-visited land on earth over the following three days.

After landfall over the archipelago, the storm is forecast to emerge into the South China Sea and undergo a few rounds of intensification to grow into a likely typhoon, before making a landfall over Thailand.

From here, the typhoon remnant is shown as tracking south to south-west over Indo-China to almost slip into the extreme south-east Bay of Bengal by November 4, up to which forecasts were available on Sunday.

WIND PATTERN

The IMD update on Sunday said that northwesterly to northerly winds were prevailing over northwest, east and central India.

A trough extended from Arunachal Pradesh to south Bay of Bengal in the lower levels of the atmosphere with an embedded cyclonic circulation over the central Bay.

The north-to-south flows occasioned by the trough are expected to cause the pre-existing upper air cyclonic circulation over southeast Bay to move west-southwest (towards the Sri Lankan latitude).

Some international models suggested that the circulation may dig further south where it would be positioned to pump up the easterly flows over peninsular India during the next week and enhance the northeast monsoon performance.

Meanwhile, maximum temperatures were above normal by 2 to 5 deg Celsius over the west and east coasts of India; by 2 to 4 deg Celsius over many parts of the north-eastern States, central and interior peninsular India.

But, they were below normal by 3 to 6 deg Celsius over most parts of northwest, central and east India, Andhra Pradesh, Maharashtra and north interior Karnataka.